When you hear the word melatonin, you probably think of sleep. After all, it’s the hormone best known for helping your body recognize when it’s time to wind down for the night. Millions of people are familiar with melatonin supplements as a way to support their sleep cycles, but there’s another side to this hormone that doesn’t get nearly as much attention.
Your digestive system produces melatonin too. And surprisingly, researchers have been investigating whether it could play a role in protecting the esophagus and reducing symptoms of acid reflux.
It’s an unexpected connection, especially when you consider that acid reflux and sleep problems often go hand in hand. So, what does melatonin actually do in your digestive system, and what has science discovered about its potential benefits?
What Does Melatonin Have to Do With Digestion?
Most of the melatonin you’ve probably heard about comes from the pineal gland, which is a small structure in the brain that releases melatonin in response to darkness. This helps regulate your circadian rhythm, so you feel tired at night.
However, the pineal gland isn’t the only place melatonin is produced. Researchers have found that cells throughout the gastrointestinal tract also produce this hormone, and its role there appears to be quite different from its familiar role in sleep (1). Rather than simply responding to darkness, melatonin in the gut is associated with digestive activity and may help regulate several processes involved in maintaining a healthy digestive system.
Scientists have been particularly interested in its protective properties. Research suggests that melatonin participates in regulating digestive secretions, influencing gastrointestinal movement, and protecting the delicate tissues lining the digestive tract (2). These functions raise an intriguing possibility: Could melatonin also influence what happens when stomach acid travels into the esophagus?
To understand why researchers are asking this question, we first need to look at what causes acid reflux.
Why Does Acid Reflux Happen?
Between your esophagus and stomach is a ring of muscle called the lower esophageal sphincter, or LES. It is essentially a valve that opens to let food enter your stomach and then closes to help keep stomach contents from flowing backward.
When this valve relaxes at the wrong time or doesn’t close properly, stomach acid can travel upward into the esophagus. Unlike your stomach, which has a protective lining designed to tolerate digestive acids, your esophagus is much more sensitive to repeated acid exposure. That’s why reflux can cause the familiar burning sensation known as heartburn, along with regurgitation, irritation, and discomfort.
Acid reflux can be particularly troublesome at night because lying down makes it easier for stomach contents to move upward. People who experience frequent nighttime reflux may find themselves waking up with heartburn, coughing, or an unpleasant acidic taste in their mouths. Over time, these interruptions can affect sleep quality and leave them feeling tired the following day.
Because reflux involves both the movement of stomach contents and irritation of the esophageal lining, researchers have been interested in substances that might influence these processes. Melatonin is one of them.
Three Ways Melatonin May Influence Acid Reflux
Melatonin’s potential relationship with acid reflux isn’t based solely on its effects on sleep. Experimental studies suggest that the hormone may influence several of the mechanisms involved in reflux and gastrointestinal protection.
One possibility involves the lower esophageal sphincter itself. Researchers have proposed that melatonin may influence the activity of this muscle, potentially through interactions with digestive hormones such as gastrin (3). Since the LES helps prevent stomach contents from traveling upward, maintaining its normal function is important for limiting reflux. However, while this mechanism has been explored experimentally, researchers have not yet established how consistently melatonin supplementation affects sphincter function in humans.
Another area of interest is melatonin’s ability to help protect digestive tissues against oxidative stress (4). When stomach acid repeatedly comes into contact with the esophageal lining, it can contribute to irritation and tissue damage. Melatonin has antioxidant properties, and research suggests it may help protect gastrointestinal tissues from certain forms of cellular damage. Researchers have also investigated its influence on local blood flow and other protective mechanisms that help maintain the digestive lining. (5,6)
Finally, melatonin may influence the regulation of stomach acid secretion (7). Some experimental studies suggest that it interacts with pathways involved in controlling digestive acid production, although these effects are complex and not yet fully understood. It’s also worth remembering that stomach acid isn’t inherently harmful. Your body needs it to digest food and perform other important functions. With acid reflux, the primary problem is that stomach contents travel into the wrong place, not necessarily that your stomach produces too much acid.
Taken together, these findings suggest that melatonin may be involved in several aspects of gastrointestinal health. But what happens when researchers actually give melatonin to people experiencing acid reflux?
Why Approved Science Includes Melatonin in Acid Reflux Support
Melatonin’s potential benefits for acid reflux aren’t limited to laboratory findings. Human studies have also produced encouraging results. In a 2023 clinical trial involving 78 participants with GERD, researchers found that adding 3 mg of melatonin to omeprazole led to greater improvements in heartburn, upper abdominal pain, and quality of life compared with omeprazole alone. (8)
Researchers have also explored higher doses. In a published case report from 2008 involving a woman with persistent acid reflux, a supplement containing 6 mg of melatonin was associated with significant symptom improvement. Interestingly, her reflux symptoms returned when the dosage was reduced to 3 mg. Although this was a single case involving other ingredients, it adds to the growing interest in melatonin’s potential for digestive support. (9)
These findings help explain why Approved Science® Acid Reflux Support includes 6 mg of melatonin per serving. The formula draws on research into melatonin’s potential role in digestive protection while combining it with other ingredients selected to support digestive comfort. For example, our formula also contains other ingredients that were used in the 2008 study, such as Betaine, L-Taurine, Calcium, Folic Acid, and more.
Learn more about the ingredients in Approved Science® Acid Reflux Support.
The Bottom Line
If acid reflux is keeping you up at night, you know how frustrating it can be to finally get comfortable in bed, only to feel that familiar burning sensation. And when it starts interfering with your sleep, the discomfort can follow you into the next day.
While most people associate melatonin with sleep, research suggests it may also play a role in protecting the digestive system and supporting esophageal health. Although more studies are needed, these findings offer an interesting new perspective on a hormone you probably thought you already knew.
That’s part of the thinking behind Approved Science® Acid Reflux Support. With 6 mg of melatonin alongside complementary ingredients selected for digestive comfort, the formula is designed to support your digestive system as you settle in for the night. Simply take it 30 minutes before bed as directed.
Because a good night’s rest is much easier to enjoy when digestive discomfort isn’t getting in the way.